Despite advances in cancer therapy, the majority of cancer therapeutics in use still exhibit significant toxicity and induce DNA damage. The DNA damage, though toxic to non-malignant cells, often plays an important role in killing cancer cells through the induction of p53. Recently, in order to develop less toxic and more targeted cancer therapies, alternative strategies to induce p53 have been proposed. One strategy involves disrupting p53 interactions with its negative regulators, HdmX and/or Hdm2. In our phase 1 grant we identified, CTX1, a novel small molecule inhibitor of HdmX/p53 that can disrupt HdmX/p53 interactions and lead to p53 induction and cancer cell death in a non-DNA damage dependent fashion. CTX1 can directly interact with HdmX and preferentially kill cancer cells expressing p53. As expected, the activity of CTX1 is enhanced by concurrent Hdm2 inhibition. Nonetheless, this compound demonstrates promising activity even as a single agent in a mouse model of circulating primary human AML. The goal of this proposal is to develop an optimized version of our HdmX inhibitor that we identified during our phase 1 grant towards clinical trials. The aims of this proposal are to assess the clinical potential of this agent through mouse efficacy, pharmacokinetic and toxicity studies. It is hoped that this work will lead to the initiaton of IND-enabling studies and the initiation of a phase 1 clinical trial.